One of Harper Lee's main themes in her novel, To Kill a Mockingbird, is the need for a second reconstruction of social consciousness in the slow-to-change Deep South of the 1930s. She crafts many examples of good and bad judgment to emphasize these ideas within her story.
PREJUDICE: Tom Robinson's greatest mistake is showing sympathy for Mayella Ewell--an emotion a black man could not afford to display toward a white woman in Alabama at this time.
"You felt sorry for her, you felt sorry for her?" Mr. Gilmer seemed ready to rise to the ceiling.
The witness realized his mistake and shifted uncomfortably in his chair. But the damage was done.
TOLERANCE: Most of the town--and all of the jury--were ready to accept the words of Bob and Mayella Ewell, considered to be from the worst family in Maycomb, over those of the simple black man, Tom Robinson. Atticus had earlier remarked to his brother, Jack
"... The evidence boils down to you-did--I didn't. The jury couldn't possibly be expected to take Tom Robinson's word against the Ewells'..."
Atticus reminds the jury in his summation to
... do your duty... ' In the name of God, believe him.' "
But it was a lost cause from the start.
EDUCATION: Harper Lee repeatedly mocks the various deficiencies in modern education. Scout is told on the first day of school to stop letting her father teach her, since what he was teaching her was wrong.
"It's best to begin reading with a fresh mind. You tell him I'll take over from here and try to undo the damage--"
Her later teacher preaches about the bigotry displayed by Hitler, but treats others in much the same way.
"... (Miss Gates) was talking with Miss Stephanie Crawford. I heard her say it was time somebody taught 'em a lesson, they were gettin' way above themselves, an' the next thing they think they can marry us."
INNOCENCE: There are many characters that reflect an innocent view of the world--particularly Tom, Boo, Jem and Scout. Boo's innocence was lost at an early age, but as he ascends from adulthood toward middle age, his insistence on reclusiveness displays a desire to return to a simpler time. Atticus urges his children to let him be, and Sheriff Tate solidifies this belief at the end.
"... taking the one man who's done you and me and this town a great service an' draggin' him with his shy ways into the limelight--to me that's a sin... If it was any other man it'd be different. But not this man, Mr. Finch."